
Photo: Paul venterCC BY-SA 3.0via Wikimedia Commonsresized / cropped
Spiny Burrweed Plant Care
Acanthospermum australe (Loefl.) Kuntze
Updated · Sources · How we source care data
Acanthospermum australe (Paraguayan starburr, ihi kukae hipa, Paraguay bur, Paraquay starbur, pipili, sheepbur, or spiny-bur) is a South American species of herbaceous plants first described as a species in 1758.
Every 7–10 days
Full sun to partial shade
60–85°F
40–70%
At a glance
How do you care for Spiny Burrweed?
Plant Spiny Burrweed in full sun to partial shade (USDA zones 13a) and water a young shrub every 7–10 days until it is established. It tolerates temperatures of 60–85°F (16–29°C). Fertilize it every 6 months during the growing season.
What Is the Spiny Burrweed?
Spiny Burrweed (Acanthospermum australe) belongs to the Asteraceae family within the Acanthospermum genus. Spiny Burrweed is also known as Goathead, Acanthospermum brasilianum, Acanthospermum hirsutum.
Spiny Burrweed displays a low spreading groundcover growth habit, reaching up to 0.5 ft tall with a spread of approximately 1.5 ft. Spiny Burrweed produces small yellow daisy-like flowers in clusters.
Leaf size: approximately 2 inches.
How Often Should You Water a Spiny Burrweed?
Water a young or newly planted Spiny Burrweed every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.
Watering Frequency
Every 7–10 days
Until established; then in dry spells
What Light Does the Spiny Burrweed Need?
Spiny Burrweed thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Spiny Burrweed Prefer?
Acanthospermum australe tolerates temperatures of 60–85°F. Spiny Burrweed prefers humidity levels of 40–70%.
Temperature
60–85°F
Humidity
40–70%
What Soil Mix Works Best for a Spiny Burrweed?
Well-draining sandy soil mix with added organic matter. Good drainage is essential for Spiny Burrweed to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Spiny Burrweed?
Feed Spiny Burrweed every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.
Stop feeding by late summer so new growth can harden before winter.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
Where Should You Plant a Spiny Burrweed?
Choose a spot with full sun to partial shade and well-draining sandy soil mix with added organic matter. Avoid low spots where water collects after rain.
Spiny Burrweed is suited to USDA Zone 13a.
Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.
How Far Apart Should You Plant a Spiny Burrweed?
Spiny Burrweed can spread to about 2 ft (0.5 m) and reach about 1 ft (0 m) tall. Space plants about 2 ft (0.5 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.
Planning a row or hedge? Try the plant spacing calculator.
How Do You Prune a Spiny Burrweed?
Prune Spiny Burrweed while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.
If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.
How Do You Care for a Spiny Burrweed in Winter?
Spiny Burrweed is frost-tender (hardy to USDA zone 13). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.
How Do You Propagate a Spiny Burrweed?
Spiny Burrweed can be propagated through seeds, stem cuttings. Similar propagation techniques also apply to bristly starbur plant care, which shares the same genus.
Is the Spiny Burrweed Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Spiny Burrweed, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Spiny Burrweed?
Spiny Burrweed is susceptible to aphids, whiteflies, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Spiny Burrweed Need?
Spiny Burrweed grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. In cooler regions, grow Spiny Burrweed as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 13a
Keep exploring plants
Spiny Burrweed is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Acanthospermum genus — compare its care with other Acanthospermum species on PlantoScan.
Acanthospermum is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Spiny Burrweed thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Acanthospermum australe (Loefl.) Kuntze, family Asteraceae (first published in Revis. Gen. Pl. 1: 303. 1891 [5 Nov 1891]) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Spiny Burrweed, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Paul venter, CC BY-SA 3.0, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 13a, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
